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Biomedical subjects

E Vidor

Publications and source records attributed to E Vidor.

34 records · Page 2Linked to original sources
PubMed1993

Serological diagnosis of leishmaniasis: on detecting infection as well as disease.

Serological tests are very frequently used in epidemiological surveys of leishmaniasis and other parasitoses. Their sensitivity and specificity are generally defined with respect to parasitism and disease, rather than infection. The reason is that known positives are those individuals most likely to yield parasites, or who have distinctive clinical signs, and concomitantly high antibody titres. This paper investigates the performance of one serological method, the indirect fluorescent antibody test (IFAT), in detecting Leishmania infantum infection during an intensive 2-year cohort study of dogs in southern France. The results show that sensitivity and specificity with respect to infection can be simultaneously high, but maximum sensitivity is probably < 80%, and lasts for a relatively short period of 2-3 months after a lengthy incubation period. The IFAT gave the incidence of infection as 18-65% in the first year, whereas the best estimate of incidence based on parasite isolation and clinical observation was 72%. But data from the second year suggest that the 72% was itself an underestimate. We argue that, during epidemiological surveys, the IFAT in particular, and serological tests for leishmania in general, will underestimate prevalence, incidence and hence the scale of the control problem. However, there is evidence that tests for canine leishmaniasis employing high threshold titres will identify the most infectious animals, allowing selective treatment or culling of those which contribute disproportionately to transmission.

Animals↗
PubMed1991

Serological evaluation of Ehrlichia canis infections in military dogs in Africa and Reunion Island.

Sixty-eight dogs from four African countries and Reunion Island were tested for antibodies against Ehrlichia canis. Twenty-six dogs (50%) in Tunisia, Senegal and Chad were found positive using the indirect fluorescence antibody test. Dogs from both the Central African Republic and Reunion Island were all negative. Thus, this preliminary report confirms the presence of E. canis in Africa. Larger studies will be necessary to evaluate the current epidemiologic situation of canine ehrlichiosis in these countries.

Animals↗
PubMed1990

Identification of major Babesia divergens polypeptides that induce protection against homologous challenge in gerbils.

[35S]methionine-radiolabeled proteins from the Babesia divergens Rouen 1987 isolate were immunoprecipitated with immune sera from three potential hosts: human, ox, and gerbil. The results showed a constant humoral response against major babesial antigens. Similarly, immunoprecipitation of radiolabeled in vitro culture supernatant demonstrated that the exoantigens of 37, 46, 70, and 90 kDA were the immunodominant polypeptides, whatever the host. The effects of vaccination with concentrated supernatant from B. divergens Rouen 1987 in vitro cultures (30 to 40% parasitemia) were examined in gerbils inoculated with the homologous B. divergens isolate. Gerbils having received two or three injections of a whole vaccine dose (1.5 ml of parasitized culture supernatant equivalent [PCSE]) or of a 1:5 diluted vaccine dose (0.3 ml of PCSE) showed 100% survival after intraperitoneal challenge with 10(6) B. divergens-infected gerbil erythrocytes. Moreover, two or three injections of a 1:25 diluted vaccine dose (0.06 ml of PCSE) or 9% NaCl or 1.5 ml of unparasitized culture supernatant equivalent resulted in a mortality rate of 80 to 90% of the infected gerbils. Immunoprecipitation and immunofluorescence assays performed with antisera from vaccinated and control gerbils demonstrated that a single vaccine injection induced a humoral response, which increased slightly after the second or third injection. After challenge, antibody levels increased significantly, although the immunoprecipitation did not display any modification of Babesia antigen patterns.

Animals↗
PubMed1989

Lack of co-transmission of Rickettsia conorii and Ehrlichia canis in human beings in the south of France.

Ehrlichia canis is the agent of canine Ehrlichiosis, commonly known as canine tropical pancytopenia. This canine disease is frequent in our area, as is Mediterranean Spotted Fever in humans. Recently a few cases of human Ehrlichiosis have been described in the USA. The supposed vector of both diseases is Rhipicephalus sanguineus. In order to evaluate the co-transmission of these two diseases, we selected 498 human sera positive for R. conorii and tested them for Ehrlichia canis. None of them were positive, suggesting the lack of co-transmission of the diseases.

Animals↗
PubMed1989

Vaccination against canine babesiosis: an overview of field observations.

Pirodog (ND) is a novel vaccine against canine babesiosis. It is commercially distributed and has been used in France since May 1988. More than 150,000 dogs have now been vaccinated and the results of the immunization have been contradictory. Many things remain to be understood concerning individual susceptibility, the immunosuppressive effect of the disease, and the incidence of concomitant infections.

Animals↗
PubMed1987

Host serum protein levels in cysts of human hydatidosis.

8 proteins (albumin, IgG, IgM, IgA, C3c, C4, orosomucoid and alpha 1 antitrypsin) were determined by laser immunonephelometry in hydatid cyst fluid from cysts and sera from 16 patients. The cystic level of albumin was 34.5 +/- SD 59.1 micrograms/ml (range 3.6-85); of IgG 12.9 +/- 18.7 micrograms/ml (1.9-75); of IgM 10.5 +/- 10.4 micrograms/ml (3-37); and of IgA 7.2 +/- 3.5 micrograms/ml (4-19.7). The 4 other proteins represented a smaller fraction: C3c, 0.9 +/- 0.6 micrograms/ml (0.5-2.5); C4, 1.3 +/- 0.9 micrograms/ml (0.5-3.5); orosomucoid, 2.8 +/- 2.3 micrograms/ml (1.4-9.2); and alpha 1-antitrypsin, 5 +/- 4.5 micrograms/ml (2-19). These 8 host proteins constituted 24.6 +/- 24.5% (2.4-76) of the total hydatid cyst fluid proteins (343.7 +/- 172.1 micrograms/ml, range 180-900). The albumin/IgG ration of 3 +/- 2.8 (0.4-10.8) in hydatid cyst fluid was more variable than that in sera, 2 +/- 0.5 (1.2-2.7).

Blood Proteins↗
PubMed1986

[Hydatid cyst fluid (Echinococcus granulosus) biochemistry. Influence of site on cyst permeability].

Eleven metabolites were determined in 19 hydatid cyst fluids of variable size and localization, and in patients plasma before surgery. Specific indirect immunofluorescent antibody titration was carried out. Sodium (132 +/- 5.2 mmol/l), chloride (92.9 +/- 6.5 mmol/l) and bicarbonate (22.1 +/- 1.5 mmol/l) were found at the same concentration than in plasma. Potassium (5.4 +/- 0.3 mmol/l) and calcium levels (4.7 +/- 0.9 mmol/l) were higher than in plasma, and phosphate (0.1 +/- 0.03 mmol/l) decreased tenfold. Glucose (3.4 +/- 0.8 mmol/l), creatinine (39.3 +/- 7.2 mumol/l) and urea nitrogen (4.6 +/- 0.8 mmol/l) showed great variations. Cholesterol levels 0.06 +/- 0.03 mmol/l) were a hundredfold lower than in plasma. Total protein levels (0.34 +/- 0.09 g/l) were found at very low concentrations. Extra-pulmonary cysts showed significantly higher antibody titers than pulmonary cysts. No correlation was observed between the size of the cysts and the level of the immune response. Significant difference about the relative cholesterol concentration (cystic concentration/plasmatic concentration) was observed between pulmonary and extra-pulmonary cysts (respectively 0.0048 +/- 0.0032 and 0.018 +/- 0.01--p less than 0.05). No correlation was observed between the size of the cyst, or the corresponding levels of the immune response, and the cholesterol levels. The hypothesis of a greater membrane permeability in extra-pulmonary cyst is discussed.

Antibodies↗
PubMedDate not supplied

[Canine ehrlichiosis in Senegal: human and canine seroepidemiological survey in Dakar].

Since 1986, several cases of human ehrlichiosis due to Ehrlichia canis have been reported in the U.S.A. Suspecting a pathology transmissible from dog to man the authors conducted an epidemiologic survey in an ehrlichiosis zone in Senegal on a population of 42 men and 66 dogs. In 1987, this rickettsiosis accounted for the deaths of a good half of the military dogs stationed in Dakar. Yet two years after implementing a prophylactic policy the seroprevalence rate in the kennel dropped from 53% to 13%. Among the dog population of the Gendarmerie Nationale Sénégalaise, the seroprevalence rate is very high (78%) and in the sample of civil, native dogs, seroprevalence was 37%. The fact that no positive human serology was observed among the working-dog handlers in permanent contact with the infected dogs leads the authors to conclude that man is not receptive to Ehrlichia canis.

Animals↗
PubMedDate not supplied

[Clinical development of a new inactivated hepatitis A vaccine].

An attenuated vaccine against hepatitis A was developed from the GBM strain of the virus, cultured on human diploid MRC5 cells. Each dose contained 160 antigen units, inactivated by formalin and adsorbed onto 0.3 mg aluminum hydroxide, in a volume of 0.5 ml. Intramuscular injection of the vaccine conferred immunity to hepatitis A, with antibody titers greater than those obtained by passive immunization with immunoglobulin. In clinical studies, immunocompromised subjects became immune shortly after the first injection and more than 90% were found to be protected after 14 days (titer above 20 mIU/ml by RIA). All subjects (100%) were protected one month after the first injection. Immunity persisted for at least six months and was strengthened by a booster injection. The antibody titers determined after the first booster injection were consistent with a projected period of protection of ten years. Adverse reactions were mild and occurred within the first few days after vaccination, with the patient usually recovering spontaneously. The most common reaction was mild local pain, usually associated with redness of the skin. A nodule was observed at the injection site in a small number of cases. Mild fever, asthenia, headache, myalgia/arthralgia and gastrointestinal tract disorders were also reported. Reactions were reported less frequently after the booster injection than after the initial dose. The vaccine was as well tolerated by patients seropositive for the hepatitis A virus as by seronegative subjects. Thus, this vaccine can be used for active immunization against hepatitis A in adults and adolescents. It can be administered as primary immunization and as a booster injection.

Adolescent↗